1. Field of the Invention:
An improved flashing for roof top vent pipes, characterized by a sealing collar of soft, elastomeric material which is frustoconical and further is intended to be mounted upon a frustoconical flashing base member, or integrated into a one-piece flashing. The invention resides in the manner of permitting separations of individual annular rings, so that a single flashing can be used to accommodate a plurality of differing diameter vent pipes.
2. Brief Description of the Prior Art:
The present invention represents a structural improvement upon the sealing collar taught within applicant's prior patent, HASTY, U.S. Pat. No. 4,563,847. As in applicant's prior patent, the present invention permits a single flashing to accommodate more than one vent pipe diameter, wherein larger vent pipe diameters are sealed simply by separating one or more annular rings through a frangible disconnect within the sealing ring collar. The elastomeric collar of the present invention may be overmolded upon a hard plastic base using the technique taught by my pending application Ser. No. 07/136,610, which is incorporated herein by reference for that disclosure. The elastomeric collar of the present invention also may be mounted by crimping onto a hard base of galvanized steel or aluminum, for example. Finally, the elastomeric collar of the present invention may be part of a flashing totally comprised of elastomeric material, and molded in a single unit, in a manner somewhat analogous to the one-piece construction of U.S. Pat. No. 4,563,847.
Examples of other prior art two-piece flashings, having a soft collar and a hard base mounting are LOGSDON (U.S. Pat. No. 4,265,058) and KEIFER (U.S. Pat. No. 4,526,407). The use of two concentric sealing rings, as employed with the present invention, for a single vent pipe diameter is disclosed by KEIFER (U.S. Pat. No. 3,313,559), whereby there will be an overall wiping action by the elastomeric collar. The wiping is effected through distension of a rubber circular element, with at least two concentric rings making contact upon the vent pipe. With respect to use with a metal hard base, wherein an elastomeric collar is to be held in a C-clamp engagement by a corrugated metal flange, such an interconnection per se is shown by FIFE (U.S. Pat. No. 1,258,884) and BUCKLES et al. (U.S. Pat. No. 1,615,929).
Unlike such prior art devices, the present invention is distinguished by a novel elastomeric collar, wherein individual annular rings are separated by pulling on vertically extending tabs, to define a circular sealing that will accommodate, respectively, a 1.5 inch vent pipe, a 2 inch vent pipe, or a 3 inch vent pipe, for example. While the present invention preferred embodiments show sealing arrangements for three vent pipe diameters, the invention also contemplates adding an additional annular ring (and a secondary sealing ring shoulder or vertical sealing tube) for a 4-inch vent pipe. Four embodiments of the present invention incorporate primary and secondary sealing, wherein distension of the first annular sealing surface is greater than that of the second sealing ring shoulder surface, as part of a novel universal vent pipe size flashing. Unlike the prior art, the present invention teaches a universal type of elastomeric collar wherein primary and secondary sealing is not compromised by the fact that individual end-rings easily are ripped off from the top. The use of upwardly extending pull tabs, and associated primary frangible sections, prevents weakening of the elastomeric collar at outer annular rings not intended to be disturbed, during the ripping of an inner annular ring. A fifth embodiment covers the top of a vent pipe, and thereby seals the entire outer surface of the vent pipe.